Hitch apparatus for attaching and detaching a bucket or other type of material handler from the boom of a backhoe or excavation vehicle are well known and widely used. Exemplifying hitch apparatus of various prior types are the disclosures in U.S. Pat. Nos. 2,447,150; 3,237,795; 3,389,819; 3,794,195; 3,874,533; 3,934,738; 4,127,203; 4,187,050; 4,295,287; 4,311,428; and 4,436,477.
Contributing to the design considerations of such prior hitch units are compatibility between the material handling tool and vehicle, the relative permanency once assembled and/or the attendant problems associated with attachment and detachment when change of the material handling tool is required. The changing of material handling tools mounted on a backhoe dipperstick traditionally has been laborious and time consuming. In recent years considerable effort has been expended toward simplifying this task by connecting different tools to, rather than replacing, the bucket; and by providing connecting mechanisms on the tool and dipperstick which reduce the time and effort required for tool changeover. Such schemes have suffered from various drawbacks, principal of which are the need for precise vertical alignment of the tool and dipperstick, the inability of the backhoe operator either to change tools himself or to make the change without leaving his seat, the necessity of manually locking each tool to the dipperstick or bucket, the danger presented by improperly or incompletely connected tools, and the requirement that a different set of tools be provided for each size or type of backhoe.
The various structures and mechanisms known for that purpose differ somewhat from each other both in their construction and ease of operation in their ability to effect a changeover of a bucket or other material handling attachment as exemplified by the disclosures of the prior patents noted above. In a basic procedure, however, interchange is accomplished by removing two pins that normally secure a bucket to the dipperstick and the linkage, exchanging the bucket and then replacing the pins. Often, and particularly acute after a considerable number of changeovers, the pins must be hammered in and out resulting in damage to the pins themselves as well as the bucket bushings, the linkage arms and/or the dipperstick. In addition, shims are commonly utilized to take up any lateral spacing between the bosses on the bucket and the dipperstick such that alignment of the shims when replacing the pins increases the attendant difficulty of the interchange procedure.
Despite recognition of the foregoing a more ready solution has not heretofore been known.